org.icesquirrel.jsr223.IcesquirrelScriptEngine.java Source code

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Here is the source code for org.icesquirrel.jsr223.IcesquirrelScriptEngine.java

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/** 
 * The MIT License (MIT)
 *
 * Copyright (c) 2014-2016 Emerald Icemoon (emerald.icemoon@gmail.com)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and 
 * associated documentation files (the "Software"), to deal in the Software without restriction, 
 * including without limitation the rights to use, copy, modify, merge, publish, distribute, 
 * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is 
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all copies or substantial 
 * portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING 
 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package org.icesquirrel.jsr223;

import java.io.Reader;
import java.io.StringReader;
import java.lang.reflect.Method;
import java.util.List;
import java.util.Map.Entry;

import javax.script.AbstractScriptEngine;
import javax.script.Bindings;
import javax.script.ScriptContext;
import javax.script.ScriptEngineFactory;
import javax.script.ScriptException;
import javax.script.SimpleScriptContext;

import org.apache.commons.io.input.ReaderInputStream;
import org.icesquirrel.interpreter.SquirrelInterpretedProcessor;
import org.icesquirrel.interpreter.SquirrelInterpretedScript;
import org.icesquirrel.runtime.BridgeSquirrelClass;
import org.icesquirrel.runtime.JavaSquirrelObject;
import org.icesquirrel.runtime.SquirrelArray;
import org.icesquirrel.runtime.SquirrelException;
import org.icesquirrel.runtime.SquirrelExecutionContext;
import org.icesquirrel.runtime.SquirrelObjectWrapper;
import org.icesquirrel.runtime.SquirrelRuntime;
import org.icesquirrel.runtime.SquirrelTable;

public class IcesquirrelScriptEngine extends AbstractScriptEngine {

    private IcesquirrelScriptEngineFactory factory;

    IcesquirrelScriptEngine(IcesquirrelScriptEngineFactory factory) {
        this.factory = factory;
    }

    @Override
    public Object eval(String script, ScriptContext context) throws ScriptException {
        return eval(new StringReader(script), context);
    }

    @Override
    public Object eval(Reader reader, ScriptContext context) throws ScriptException {

        SquirrelInterpretedScript sis = new SquirrelInterpretedScript();

        /*
         * If the global bindings is already a SquirrelTable, use that directly.
         * A squirrel table is kind of compatible with a bindings object, except
         * the key may be an Object instead of a string.
         */
        Bindings bindings = context.getBindings(ScriptContext.GLOBAL_SCOPE);
        if (bindings instanceof BindingsAdapter) {
            sis.setRootTable(((BindingsAdapter) bindings).getTable());
        } else {
            // Otherwise copy global bindings into our root table
            for (Entry<String, Object> s : bindings.entrySet()) {
                bind(sis, s);
            }
        }

        // Now the engine scoped bindings. If these are already a squirrel
        // table, add them as
        // a delegate, otherwise copy
        Bindings engBindings = context.getBindings(ScriptContext.ENGINE_SCOPE);
        SquirrelTable addedDelegate = null;
        if (engBindings instanceof BindingsAdapter) {
            BindingsAdapter ba = (BindingsAdapter) engBindings;
            if (ba.getTable() != sis.getRootTable()) {
                SquirrelTable pt = sis.setRootTable(ba.getTable());
                if (pt != null && !ba.getTable().getDelegates().contains(pt)) {
                    ba.getTable().addDelegate(pt);
                    addedDelegate = pt;
                }
            }
        } else {
            for (Entry<String, Object> s : engBindings.entrySet()) {
                bind(sis, s);
            }
        }

        SquirrelRuntime runtime = SquirrelRuntime.getDefaultRuntime();
        SquirrelExecutionContext ctx = null;
        if (!SquirrelExecutionContext.is()) {
            ctx = new SquirrelExecutionContext();
            ctx.start(sis.getRootTable(), runtime, new SquirrelInterpretedProcessor());
        }

        try {
            try {
                // TODO encoding
                sis.execute(new ReaderInputStream(reader));
            } catch (SquirrelException se) {
                // TODO line number etc
                throw new ScriptException(se);
            } catch (Exception e) {
                // TODO line number etc
                throw new ScriptException(e);
            }
            Object result = sis.getResult();
            if (result instanceof SquirrelObjectWrapper) {
                return ((SquirrelObjectWrapper) result).getObject();
            }
            return result;
        } finally {
            if (addedDelegate != null) {
                sis.getRootTable().removeDelegate(addedDelegate);
            }
            if (ctx != null) {
                ctx.stop();
            }
        }
    }

    private void bind(SquirrelInterpretedScript sis, Entry<String, Object> s) {
        Object value = s.getValue();
        if (value instanceof Class<?>) {
            value = new BridgeSquirrelClass((Class<?>) value);
        } else if (value instanceof Method) {
            BridgeSquirrelClass.BridgeSquirrelFunction bridgeSquirrelFunction = new BridgeSquirrelClass.BridgeSquirrelFunction(
                    ((Method) value).getDeclaringClass());
            bridgeSquirrelFunction.getMethods().add((Method) value);
            value = bridgeSquirrelFunction;
        } else if (value instanceof List) {
            value = new SquirrelArray((List) value);
        } else if (value instanceof Object) {
            value = new JavaSquirrelObject(new BridgeSquirrelClass(value.getClass()), value) {
            };
        }
        sis.getRootTable().insertLocal(s.getKey(), value);
    }

    @Override
    public Bindings createBindings() {
        return new BindingsAdapter(new SquirrelTable());
    }

    @Override
    public ScriptEngineFactory getFactory() {
        return factory;
    }

    class SquirrelContext extends SimpleScriptContext {

    }
}